Our objectives are to study DNA repair in specific sequences of the genome with a regard to implications for carcinogenesis and cancer therapy. A method was previously developed to study DNA repair in specific genomic sequences after UV damage. This has allowed us to study the DNA repair efficiency in a number of genes in various mammalian cells. DNA repair characteristics in genes have been compared to those in noncoding genomic sequences and to overall genome DNA repair measurements. The results suggest that DNA repair studies in genes are very important when correlating to other biological endpoints such as cellular resistance to carcinogens. Fine structure analysis of DNA repair in different regions of a gene locus suggest that preferential DNA repair exists within a 60-80 kb region which is likely to coincide with a higher order structure loop or domain in chromatin. Some review papers have recently been submitted. Lately, we have discovered that DNA repair efficiency is positively correlated with the level of transcription. Activation of genes enhance the rate with which they are repaired.